The invention relates to a process executed in a computer system to avoid physical input/output (I/O) by intercepting access-method requests for read and write to disk.
Microfiche appendixes, containing a total of 519 frames and 7 fiche 1, 2, and 3 set out copyrighted selected source code extracts and by a general use information concerning a commercial software package distributed by the assignee of this application which manifests the invention. Permission is granted to make copies of the appendixes solely in connection with the making of facsimile copies of this application in accordance with applicable law; all other rights are reserved, and all other reproduction, distribution, creation of derivative works based on the contents, public display, and public performance of the microfiche appendixes or any part thereof are prohibited by the copyright laws.
Referring to FIG. 1, in the prior art, a user process (not shown) commonly issues a data access request, as shown at box 101. If the requested data is available in a buffer-pool memory area, as shown at box 103, the data is returned to the requesting process as shown at box 105 and execution of the data access request is terminated at box 111. On the other hand, if the data is not available in the buffer pool at box 103, a disk access method is invoked at box 107 to locate and retrieve the data from disk; commonly, the data will be copied from disk storage to a buffer pool as shown at box 109 and the data will be returned to the requesting process.